function.vhd

用于视频运动图像编码的HUFFMAN编码

library ieee;
use ieee.std_logic_1164.all;
package MYfunction is
	function vector_int(val:std_logic_vector) return integer;
	function INC8(val:std_logic_vector(7 downto 0)) return std_logic_vector;
end MYfunction;

package body MYfunction is
	function vector_int(val:std_logic_vector) return integer is
	variable result:integer:=0;
	begin	
		result:=0;
		for i in val'length-1 downto 0 loop
			result:=result*2;
			if val(i)='1' then
				result:=result+1;
			end if;
		end loop;
		return result;
	end vector_int;
	
	function INC8(val:std_logic_vector(7 downto 0)) return std_logic_vector is
	variable result:std_logic_vector(7 downto 0);
	begin
		result:=val;
		for i in 0 to 7 loop
			if result(i)='0' then
				result(i):='1';
				exit;
			else
				result(i):='0';
			end if;
		end loop;
		return result;
	end INC8;
	
end MYfunction;